Breville Hand Blender Replacement Coupling

I have a Breville "Pro Kitchen Hand Blender" (VHB089-01) which has a chopping attachment, unfortunately unlike the whisk and blender attachments which use a metal coupling, the chopping attachment has a small plastic one (see the pictures). I was chopping something harder than normal and the coupling just snapped making the attachment useless.

I designed this replacement part in Sketchup and printed it in PLA on a MakerBot Thing-O-Matic with Sailfish.